Car tax offence

[ShouldistayShouldigo]

I’m not sure if this is classed as a crime but the internet said it was an offence.

I bought a car in July 2019 and as a new, naive owner i didn’t realise that tax doesn’t transfer anymore. The person I bought it off said it was taxed and MOT til March 2020. They also didn’t give me a log book but kept saying they would send it out to me so I was waiting on it arriving.

I had to search my car details online for something a week or so ago and it came up as “untaxed”. I applied for a new log book straight away and I taxed it today when the book arrived, but got a warning notice online that they may investigate the 6/7 months that it hasn’t been taxed or declared as SORN (I didn’t know what that was either).

I have mental disabilities but not learning ones. If it matters or not I don’t know, I accept I should’ve known these things and was a bit stupid (I feel very stupid).

I’m happy to pay any fines but worried about what might happened now? Does anyone have experience? I was hoping I could backdate it but it seems that’s not possible.

Because of the log book issue I would assume any letters got sent to the previous owner, but they haven’t contacted to say anything of the sort.

Please be kind as I feel really embarrassed and worried